Inbred corn line G4803

ABSTRACT

Broadly this invention provides for an inbred corn line G4803. The methods for producing a corn plant by crossing the inbred line G4803 are also encompassed by the invention. Additionally, the invention relates to the various parts of inbred G4803 including culturable cells. This invention relates to hybrid corn seeds and plants produced by crossing the inbred line G4803 with at least one other corn line.

FIELD OF THE INVENTION

This invention is in the field of corn breeding, specifically relatingto an inbred corn line designated G4803. This invention also is in thefield of hybrid maize production employing the present inbred.

BACKGROUND OF THE INVENTION

The original maize plant was indigenous to the Western Hemisphere. Theplants were weedlike and only through the efforts of early breeders werecultivated crop species developed. The crop cultivated by earlybreeders, like the crop today, could be wind pollinated. The physicaltraits of maize are such that wind pollination results inself-pollination or cross-pollination between plants. Each plant has aseparate male and female flower that contributes to pollination, thetassel and ear, respectively. Natural pollination occurs when windtransfers pollen from tassel to the silks on the corn ears. This type ofpollination has contributed to the wide variation of maize varietiespresent in the Western Hemisphere.

The development of a planned breeding program for maize only occurred inthe last century. A large part of the development of the maize productinto a profitable agricultural crop was due to the work done by landgrant colleges. Originally, maize was an open pollinated variety havingheterogeneous genotypes. The maize farmer selected uniform ears from theyield of these genotypes and preserved them for planting the nextseason. The result was a field of maize plants that were segregating fora variety of traits. This type of maize selection led to, at most,incremental increases in seed yield.

Large increases in seed yield were due to the work done by land grantcolleges that resulted in the development of numerous hybrid cornvarieties in planned breeding programs. Hybrids were developed byselecting corn lines and selfing these lines for several generations todevelop homozygous pure inbred lines. One selected inbred line wascrossed with another selected inbred line to produce hybrid progeny(F1). The resulting hybrids, due to heterosis, are robust and vigorousplants. Inbreds on the other hand are mostly homozygous. Thishomozygosity renders the inbred lines less vigorous. Inbred seed can bedifficult to produce since the inbreeding process in corn linesdecreases the vigor. However, when two inbred lines are crossed, thehybrid plant evidences greatly increased vigor and seed yield comparedto open pollinated, segregating maize plants. An important consequenceof the homozygosity and the homogenity of the inbred maize lines is thatall hybrid seed produced from any cross of two such elite lines will bethe same hybrid seed and make the same hybrid plant. Thus the use ofinbreds makes hybrid seed which can be reproduced readily. The hybridplant in contrast does not produce hybrid seed that is readilyreproducible. The seed on a hybrid plant is segregating for traits.

The ultimate objective of the commercial maize seed companies is toproduce high yielding, agronomically sound plants that perform well incertain regions or areas of the Corn Belt. To produce these types ofhybrids, the companies must develop inbreds, which carry needed traitsinto the hybrid combination. Hybrids are not often uniformly adapted forthe entire Corn Belt, but most often are specifically adapted forregions of the Corn Belt. Northern regions of the Corn Belt requireshorter season hybrids than do southern regions of the Corn Belt.Hybrids that grow well in Colorado and Nebraska soils may not flourishin richer Illinois and Iowa soil. Thus, a variety of major agronomictraits are important in hybrid combination for the various Corn Beltregions, and have an impact on hybrid performance.

Inbred line development and hybrid testing have been emphasized in thepast half-century in commercial maize production as a means to increasehybrid performance. Inbred development is usually done by pedigreeselection. Pedigree selection can be selection in an F₂ populationproduced from a planned cross of two genotypes (often elite inbredlines), or selection of progeny of synthetic varieties, open pollinated,composite, or backcrossed populations. This type of selection iseffective for highly inheritable traits, but other traits, for example,yield requires replicated test crosses at a variety of stages foraccurate selection.

Maize breeders select for a variety of traits in inbreds that impacthybrid performance along with selecting for acceptable parental traits.Such traits include: yield potential in hybrid combination; dry down;maturity; grain moisture at harvest; greensnap; resistance to rootlodging; resistance to stalk lodging; grain quality; disease and insectresistance; ear and plant height. Additionally, Hybrid performance willdiffer in different soil types such as low levels of organic matter,clay, sand, black, high pH, low pH; or in different environments such aswet environments, drought environments, and no tillage conditions. Thesetraits appear to be governed by a complex genetic system that makesselection and breeding of an inbred line extremely difficult. Even if aninbred in hybrid combination has excellent yield (a desiredcharacteristic), it may not be useful because it fails to haveacceptable parental traits such as seed yield, seed size, pollenproduction, good silks, plant height, etc.

To illustrate the difficulty of breeding and developing inbred lines,the following example is given. Two inbreds compared for similarity of29 traits differed significantly for 18 traits between the two lines. If18 simply inherited single gene traits were polymorphic with genefrequencies of 0.5 in the parental lines, and assuming independentsegregation (as would essentially be the case if each trait resided on adifferent chromosome arm), then the specific combination of these traitsas embodied in an inbred would only be expected to become fixed at arate of one in 262,144 possible homozygous genetic combinations.Selection of the specific inbred combination is also influenced by thespecific selection environment on many of these 18 traits which makesthe probability of obtaining this one inbred even more remote. Inaddition, most traits in the corn genome are regrettably not singledominant genes but are multi-genetic with additive gene action notdominant gene action. Thus, the general procedure of producing a nonsegregating F₁ generation and self pollinating to produce a F₂generation that segregates for traits and selecting progeny with thevisual traits desired does not easily lead to a useful inbred. Greatcare and breeder expertise must be used in selection of breedingmaterial to continue to increase yield and the agronomics of inbreds andresultant commercial hybrids.

Certain regions of the Corn Belt have specific difficulties that otherregions may not have. Thus the hybrids developed from the inbreds haveto have traits that overcome or at least minimize these regional growingproblems. Examples of these problems include in the eastern corn beltGray Leaf Spot, in the north cool temperatures during seedlingemergence, in the Nebraska region CLN (corn Lethal necrosis and in thewest soil that has excessively high pH levels. The industry oftentargets inbreds that address these issues specifically forming nicheproducts. However, the aim of most large seed producers is to provide anumber of traits to each inbred so that the corresponding hybrid canuseful in a broader regions of the Corn Belt. The new biotechnologytechniques such as Microsatellites, RFLPs, RAPDs and the like haveprovided breeders with additional tools to accomplish these goals.

SUMMARY OF THE INVENTION

The present invention relates to an inbred corn line G4803.Specifically, this invention relates to plants and seeds of this line.Additionally, this relates to a method of producing from this inbred,hybrid seed corn and hybrid plants with seeds from such hybrid seed.More particularly, this invention relates to the unique combination oftraits that combine in corn line G4803.

Generally then, broadly the present invention includes an inbred cornseed designated G4803. This seed produces a corn plant.

The invention also includes the tissue culture of regenerable cells ofG4803 wherein the cells of the tissue culture regenerates plants capableof expressing the genotype of G4803. The tissue culture is selected fromthe group consisting of leaves, pollen, embryos, roots, root tips, guardcells, ovule, seeds, anthers, silk, flowers, kernels, ears, cobs, husksand stalks, cells and protoplasts thereof. The corn plant regeneratedfrom G4803 or any part thereof is included in the present invention. Thepresent invention includes regenerated corn plants that are capable ofexpressing G4803's genotype, phenotype or mutants or variants thereof.

The invention extends to hybrid seed produced by planting, inpollinating proximity which includes using preserved maize pollen asexplained in U.S. Pat. No. 5,596,838 to Greaves, seeds of corn inbredlines G4803 and another inbred line if preserved pollen is not used;cultivating corn plants resulting from said planting; preventing pollenproduction by the plants of one of the inbred lines if two are employed;allowing cross pollination to occur between said inbred lines; andharvesting seeds produced on plants of the selected inbred. The hybridseed produced by hybrid combination of plants of inbred corn seeddesignated G4803 and plants of another inbred line are apart of thepresent invention. This inventions scope covers hybrid plants and theplant parts including the grain and pollen grown from this hybrid seed.

The invention further includes a method of hybrid F1 production. A firstgeneration (F1) hybrid corn plant produced by the process of plantingseeds of corn inbred line G4803; cultivating corn plants resulting fromsaid planting; permitting pollen from another inbred line to crosspollinate inbred line G4803; harvesting seeds produced on plants of theinbred; and growing a harvested seed are part of the method of thisinvention.

Likewise included is a first generation (F1) hybrid corn plant producedby the process of planting seeds of corn inbred line G4803; cultivatingcorn plants resulting from said planting; permitting pollen from inbredline G4803 to cross pollinate another inbred line; harvesting seedsproduced on plants of the inbred; and growing a plant from such aharvested seed.

The inbred corn line G4803 and at least one transgenic gene adapted togive G4803 additional and/or altered phenotypic traits are within thescope of the invention. Such transgenes are usually associated withregulatory elements (promoters, enhancers, terminators and the like).Presently, trangenes provide the invention with traits such as insectresistance, herbicide resistance, disease resistance increased ordeceased starch or sugars or oils, increased or decreased life cycle orother altered trait.

The present invention includes inbred corn line G4803 and at least onetransgenic gene adapted to give G4803 modified starch traits.Furthermore this invention includes the inbred corn line G4803 and atleast one mutant gene adapted to give modified starch, acid or oiltraits. The present invention includes the inbred corn line G4803 and atleast one transgenic gene selected from the group consisting of:bacillus thuringiensis, the bar or pat gene encoding Phosphinothricinacetyl Transferase, Gdha gene, EPSP synthase gene, low phytic acidproducing gene, and zein. The inbred corn line G4803 and at least onetransgenic gene useful as a selectable marker or a screenable marker arecovered by the present invention.

A tissue culture of the regenerable cells of hybrid plants produced withuse of G4803 genetic material is covered by this invention. A tissueculture of the regenerable cells of the corn plant produced by themethod described above are also included.

Definitions

In the description and examples, which follow, a number of terms areused. In order to provide a clear and consistent understanding of thespecifications and claims, including the scope to be given such terms,the following definitions are provided.

BL Moist

The moisture percentage of the grain at black layer, i.e., when 50% ofthe plants per plot have reached physiological maturity.

Cold Germ

Cold Germ is a measurement of seed germination under cold soilconditions. Data is reported as percent of seed germinating.

ECB

European corn borer is a maize eating insect. ECBI is the first broodgeneration of European corn borers. ECBII is the second generation ofEuropean corn borers. ECB1 is a rating of leaf damage. The ECBII (ECB2)rating is based upon tunneling. For all Entomology ratings, the highernumber is best (1=little or no resistance, 9=highly resistant). Thescale is slightly different for Ear Rating, which is taken on a 1–4basis. This is a rating of corn borer feeding on the ear. A 1 representsfeeding over the entire ear, while a 4 represents no observable feedingon the ear.Emerge (EMG)The number of emerged plants per plot (planted at the same seedlingrate) collected when plants have two fully developed leaves.GIThis is a selection index that provides a single quantitative measure ofthe worth of a hybrid based on four traits. F1 is a very similar indexwhich weights yield less than GI. In GI yield is the primary traitcontributing to index values. The GI value is calculated by combiningstalk lodging, root lodging, yield and dropped ears according to theattached mathematical formula:GI=100+0.5(YLD)−0.9(% STALK LODGE)−0.9(% ROOT LODGE)−2.7(% DROPPED EAR)GLSGray Leaf Spot (Cercospora Zeae) disease rating. This is rated on a 1–9scale with a “1” being very susceptible, and a “9” being veryresistant.*GWGross' Wilt (Corynebacterium nebraskense). This is rated on a 1–9 scalewith a “1” being very susceptible, and a “9” being very resistant.*HEATP10The number of Growing Degree Units (GDU's) or heat units required for aninbred line or hybrid to have approximately 10 percent of the plantsshedding pollen. This trait is measured from the time of planting.Growing Degree Units are calculated by the Barger Method where the GDU'sfor a 24 hour period are:

${GDU} = {\frac{\left( {{{Max}\mspace{14mu}{Temp}\mspace{14mu}\left( {{{^\circ}F}.} \right)} + {{Min}\mspace{14mu}{Temp}\mspace{14mu}\left( {{{^\circ}F}.} \right)}} \right)}{2} - 50}$The highest maximum temperature used is 86° F. and the lowest minimumtemperature used is 50° F. For each inbred or hybrid it takes a certainnumber of GDU's to reach various stages of plant development.HEATBLThe number of GDU's after planting when approximately 50 percent of theinbred or hybrid plants in a plot have grain that has reachedphysiological maturity (black layer).HeatpeekThe number of GDU's after planting of an inbred when approximately 50percent of the plants show visible tassel extension.HEATP50 or HTP50The number of GDU's required for an inbred or hybrid to haveapproximately 50 percent of the plants shedding pollen. Growing DegreeUnits are calculated by the Barger Method as shown in the HEATP10definition.HEATP90The number of GDU's accumulated from planting when the last 100 percentof plants in an inbred or hybrid are still shedding enough viable pollenfor pollination to occur. Growing Degree Units are calculated by theBarger Method as shown in the HEATP10 definition.HEATS10The number of GDU's required for an inbred or hybrid to haveapproximately 10 percent of the plants with silk emergence of at least0.5 inches. Growing Degree Units are calculated by the Barger Method asshown in the HEATP10 definition.HEATS50 or HTS50The number of GDU's required for an inbred or hybrid to haveapproximately 50 percent of the plants with silk emergence of at least0.5 inches. Growing Degree Units are calculated by the Barger Method asshown in the HEATP10 definition.HEATS90The number of GDU's required for an inbred or hybrid to haveapproximately 90 percent of the plants with silk emergence of at least0.5 inches. Growing Degree Units are calculated by the Barger Method asshown in the HEATP10 definition.MDMV_(A)Maize Dwarf Mosaic Virus strain A. The corn is rated on a 1–9 scale witha “1” being very susceptible, and a “9” being very resistant.*MDMV_(B)Maize Dwarf Mosaic Virus strain B. This is rated on a 1–9 scale with a“1” being very susceptible and a “9” being very resistant.*MoistureThe average percentage grain moisture of an inbred or hybrid at harvesttime.NLBNorthern Leaf Blight (Exserohilum turcicum) disease rating. This israted on a 1–9 scale with a “1” being very susceptible, and a “9” beingvery resistant.*PCT Tiller or Tiller RatingThe total number of tillers per plot divided by the total number ofplants per plot.Plant

This term includes the entire plant and its plant cells, plantprotoplasts made from its cells, plant cell tissue cultures from whichcorn plants can be regenerated, plant calli, plant clumps, and plantcells that are intact in plants or parts of plants, such as embryos,pollen, flowers, kernels, ears, cobs, leaves, husks, stalks, roots, roottips, anthers, silk and the like, and this term also includes anymutated gene, transgenic DNA or (RNA) or portion thereof that have beenintroduced into the plant by whatever method.

Plant Height (PLTHT) (PHT)

The distance in centimeters from ground level to the base of the tasselpeduncle.

Plant Integrity (PLTINT) or (INT)

The level of plant integrity on a scale of 1–9 with 9 evidencing thetrait most strongly: 1–2.9 ratings are low plant integrity, 3–5.9ratings are intermediate plant integrity, and 6–9 ratings are stronglyevidencing plant integrity.

Population (POP)

The plant population.

RM

Predicted relative maturity based on the moisture percentage of thegrain at harvest. This rating is based on known set of checks andutilizes standard linear regression analyses and is referred to as theMinnesota Relative Maturity Rating System.

Shed

The volume of pollen shed by the male flower rated on a 1–5 scale wherea “1” is a very light pollen shedder, a “2.5” is a moderate shedder, anda “5” is a very heavy shedder.

SLB

Southern Leaf Blight (Bipolaris maydis) disease rating. This is rated ona 1–9 scale with a “1” being very susceptible, and a “9” being veryresistant.*

Staygreen (SGN)

The level of staygreen of the plant on a scale of 1–9 with 9 evidencingthe trait most strongly: 1–2.9 ratings are low staygreen, 3–5.9 ratingsare intermediate staygreen, and 6–9 ratings are strongly evidencingstaygreen.

TWT

The measure of the weight of grain in pounds for a one bushel volumeadjusted for percent grain moisture.

Vigor (VIG)

Visual rating of 1 to 9 made 2–3 weeks post-emergence where a “1”indicates very poor early plant development, and a “9” indicatessuperior plant development.

Warm Germ

A measurement of seed germination under ideal (warm, moist) conditions.Data is reported as percent of seeds germinating.

Yield (YLD)

Actual yield of grain at harvest adjusted to 15.5% moisture.Measurements are reported in bushels per acre.

% Dropped Ears (DE)

The number of plants per plot, which dropped their primary ear, dividedby the total number of plants per plot.

% Root Lodge (RL)

Percentage of plants per plot leaning more that 30 degrees from verticaldivided by total plants per plot.

10% Stalk Lodge (SL)

Percentage of plants per plot with the stalk broken below the primaryear node divided by the total plants per plot.

% Cull

Percentage of seed that passes through a 16/64 inch screen or will notpass through a 25/64 inch screen.

*Resistant—on a scale of 1–9 with 9 evidencing the trait most strongly:1–2.9 ratings are susceptible, 3–5.9 ratings are intermediate, and 6–9ratings are resistant.

DETAILED DESCRIPTION OF THE INVENTION

G4803 is an inbred that does not shed pollen all that well. It is betteras a female line than as a male. The present invention has a late blacklayering time in light of its 50% silking date. The present inventionshows good ratings for plant integrity for an inbred. This inbredcarries some strong disease tolerance to North Leaf Blight.

The inbred has shown uniformity and stability within the limits ofenvironmental influence for all the traits as described in the VarietyDescription Information (Table 1) that follows.

The inbred has been self-pollinated for a sufficient number ofgenerations to give inbred uniformity. During plant selection in eachgeneration, the uniformity of plant type was selected to ensurehomozygosity and phenotypic stability. The line has been increased inisolated farmland environments with data on uniformity and agronomictraits being observed to assure uniformity and stability. No varianttraits have been observed or are expected in G4803.

The best method of producing the invention, G4803 which is substantiallyhomozygous, is by planting the seed of G4803 which is substantiallyhomozygous and self-pollinating or sib pollinating the resultant plantin an isolated environment, and harvesting the resultant seed.

TABLE 1 G4803 VARIETY DESCRIPTION INFORMATION #1 Type: Dent #2 RegionBest Adapted: Broadly adapted-in regions of the Corn Belt that support106 RM hybrids. This inbred in hybrid combination usually has RM ofabout 106–107 days. #3 Plant Traits Plant Height 65 in. Ear Height 26in. Tillers (Rating) 5 Leaf Color Medium Green Brace Root ColorGREEN/RED Silk Color YELLOW/GREEN Shoots at Flowering BALD #4 TasselTraits Glume Color GREEN/PURPLE Glume Ring Color GREENISH Anther ColorREDDISH #5 Ear and Kernel Traits Cob Color Dark Red Kernel Crown ColorYELLOW Kernel Body Color ORANGE #6 Disease Resistance In Inbred Gross'Wilt = 6.2 Eye Spot = 3.5 Northern Leaf Blight = 7.3 #7 InsectResistance In Inbred ECB1 = 4.9 ECB2 = 2.3 Ear rate = 2.2 CM Tunnelling= 23.2 #8 The comparable inbred to G4803 is ZS0560 as described in U.S.Pat. No. 5,585,533. ZS0560 has a number of similarities to the presentinvention and is a parent of the line. ZS0560 is an inbred which hasbeen or is presently in a number of commercial hybrids and is related ina number of ways to G4803.

The data provided above is often a color. The Munsell code is areference book of color, which is known and used in the industry and bypersons with ordinary skill in the art of plant breeding.

The purity and homozygosity of inbred G4803 is constantly being trackedusing isozyme genotypes as shown in Table 2.

Isozyme Genotypes for G4803

Isozyme data were generated for inbred corn line G4803 according toprocedures known and published in the art. The data in Table 2 gives theelectrophoresis data on G4803.

TABLE 2 ELECTROPHORESIS RESULTS FOR G4803 Inbred ACP1 ACP4 ADH MDH1 MDH2PGD1 PGD2 PHI PGM IDH2 G4803 11 55 22 22 11 22 11 22 33 11 Parent 1 3355 22 22 11 22 11 22 22 11 Parent 2 11 00 22 22 11 22 11 22 33 22Inbred and Hybrid Performance of G4803

The traits and characteristics of inbred corn line G4803 are listed tocompare with other inbreds and/or in hybrid combinations. The G4803 datashows the characteristics and traits of importance, giving a snapshot ofG4803 in these specific environments.

Table 3A shows a comparison between G4803 and a comparable inbredZS0560, one of its parents, described in U.S. Pat. No. 5,585,533. ZS0560has significantly higher ears than does the present invention. The twoinbreds show significant differences in emergence with G4803 being thebetter inbred. The two inbreds differ significantly across all Heatmeasurements for pollination and silking. G4803 has significantly morelarge flat round seeds than does ZS0560.

PAIRED INBRED COMPARISON DATA Year Inbred Yield Moisture Ear HeightPlant Height Overall G4803 59.5 11.2 63.6 160.7 ZS0560 61.7 11.8 68.3164.5 # Expts 22.0 22.0 11.0 11.0 Diff 2.2 0.6 4.7 3.8 Prob 0.3 0.20.073* 0.1 Emerge Heat Peek Heatp10 Heatp50 Heatp90 Heats10 87.1 1326.21422.0 1461.9 1615.6 1403.0 84.5 1417.8 1492.1 1529.1 1720.2 1493.9 20.017.0 18.0 18.0 11.0 18.0 2.6 91.6 70.1 67.3 104.6 91.0 0.069* 0.000***0.000*** 0.000*** 0.000*** 0.000*** % Lrg % Lrg % Lrg % Sml Heats50Heats90 Med Flat Med Rnd Plateless Med Flat 1444.0 1497.3 20.1 33.2 3.69.0 1537.9 1575.7 14.0 37.9 4.6 4.8 18.0 11.0 20.0 20.0 20.0 20.0 93.978.4 6.1 4.8 1.0 4.1 0.000*** 0.000*** 0.000*** 0.026** 0.1 0.000*** %Sml % Sml Med Rnd Plateless % Cull Shed Cold Germ Warm Germ 23.0 7.1 3.92.6 92.0 96.4 29.3 6.1 3.1 2.9 92.9 96.4 20.0 20.0 20.0 17.0 14.0 14.06.3 1.0 0.8 0.3 0.9 0.1 0.000*** 0.1 0.061* 0.020** 0.4 0.9

TABLE 3B PAIRED HYBRID COMPARISON DATA % Root % Stalk % Drop Test YearHybrid Yield FI GI Y M Moisture Lodge Lodge per ear Weight Over-G4803/CI/ 180.5 142.1 185.7 9.8 19.1 1.8 3.3 0.1 54.8 all IT IT 179135.7 184.2 8.7 21.2 3.6 2.4 0.1 55.6 Commer- cial Hybrid/CI # Expts 187183 183 187 187 183 184 183 186 Diff 1.5 6.4 1.5 1.1 2.1 1.9 0.9 0 0.7Prob 0.161 0.000*** 0.108 0.000* 0.000*** 0.001** 0.048** 0.284 0.000**** * * *.05 < Prob <= .10 **.01 < Prob <= .05 ***.00 < Prob <= .01 CI =Common Inbred IT = Imidazolinone herbicide resistance by mutation

Table 3B shows the Inbred G4803 in a hybrid combination, which carriesthe IT herbicide tolerance gene, in comparison with another hybridcombination that has a common inbred. When in this hybrid combinationthe present inbred, G4803, carries significantly less moisture and asimilar yield into the hybrid as does the commercial hybrid with thecommon inbred. The Y/M and the root lodging for the hybrid combinationcontaining the present invention is significantly different whencompared to the competitive hybrid.

Table 4 shows the GCA (general combining ability) estimates of G4803compared with the GCA estimates of the other inbreds. The estimates showthe general combining ability is weighted by the number ofexperiment/location combinations in which the specific hybridcombination occurs. The interpretation of the data for all traits isthat a positive comparison is a practical advantage. A negativecomparison is a practical disadvantage. The general combining ability ofan inbred is clearly evidenced by the results of the general combiningability estimates. This data compares the inbred parent in a number ofhybrid combinations to a group of “checks”. The check data is from othercompanies' hybrids, particularly the leader in the industry and GarstSeed's commercial products and pre-commercial hybrids, which were grownin the same sets and locations. This Table shows that 39 differentcrosses were analyzed. Each of these crosses were made in small plotswith not less than 50 hybrid seeds being planted per cross. Theseexperiments produced progeny of G4803 by a number of different lines.The grain produced by these hybrids have the present invention as anancestor. The hybrid grain would be genetically different from thehybrid seed that formed the plant on which the hybrid grain wasproduced. However, such grain would be readily identifiable as beingprogeny of the invention or as having the invention as an ancestor.

TABLE 4 G4803 One parent in each hybrid tested to provide this data isG4803 N in N in N in YR YR YR Total 1 2 3 N FI Y M GI I YLD MST % SL %RL % DE TWT POP RM XR = 8 39 304 351 2.7 0.3 2.0 1.9 3.4 0.3 −0.1 0.40.0 −0.7 65.0 −106.0 XH = 8 39 304 38 0.9 0.1 0.8 0.6 1.2 0.1 0.1 0.00.0 −0.4 56.0 −106.0 XT = 8 39 304 2 0.8 −0.1 2.6 0.5 1.2 −0.7 −0.9 2.80.1 −1.4 31.0 107.0 XR = GCA Estimate: Weighted by Expt XH = GCAEstimate: Weighted by Parent2 XT = Same as XH but using only thoseparent2 with two years of data FI = 100 + 0.5 (YId) −2.3(MST) −0.9(% SL)−0.9(% RL) −2.7(% DE) POP = plants per acre RM = The Minnesota RelativeMaturity

Table 4 shows G4803 in XR crossed to 39 different inbreds to form hybridcombinations. G4803 in hybrid combination in XR shows an advantage foryield, yield by moisture, moisture, root lodging resistance and anadvantage for dropped ear ratings. In XT G4803 in hybrid combinationshows an excellent positive advantage for root lodging and disadvantagesfor moisture when compared to the commercial checks and the company'sother inbreds in hybrid combination.

TABLE 5A YIELD RESPONSE Research plots YIELD HYBRID A G4803/hybrid A 81108 134 161 188 215 Environment 75 100 125 150 175 200 Error: 14.7 #plots 72 HYBRID B G4803/hybrid B 74 101 128 155 182 209 Environment 75100 125 150 175 200

TABLE 5B YIELD RESPONSE Research plots HYBRID YIELD Comparison hybrid IT75 101 126 151 177 202 Environment 75 100 125 150 175 200 Error: 13.3#plots 1330

Table 5A shows the yield response of G4803 in two hybrid combinations incomparison with the plants in the environment around it at the samelocation. The data for the present inbred is showing consistently higherresults in comparison to the environment level with the exception of thevery lowest yielding environments. G4803 in hybrid combination, is veryhelpful in medium to high yielding environments. Table 5B shows the datafrom a different comparison hybrid. This comparison hybrid is yieldingat or near the expected yield levels in each environment, however itsyield is substantially lower across medium to high yielding environmentsthan is the yield potential of G4803.

TABLE 6A Agronomic Traits G4803 as hybrid 1 G4803 as hybrid 1 vs 85461TEarly # Stand Adv Emp Adv Vigor Adv S50 Adv P50 Adv 2002 18 91.5 −1.35.5 0.0 6.6 1.3 72.0 0.0 72.0 0.0 18 92.8 5.5 5.3 72.0 72.0 Ear PlantStay Black Ht. Adv Ht. Adv Green Adv Layer Adv Plant Int Adv 42.4 1.591.4 4.8 5.7 2.3 135.0 2.0 6.6 2.1 40.9 86.6 3.4 133.0 4.4The agronomic traits of the present invention are shown in two differenthybrid combinations each containing the inbred G4803. Each G4803 hybridis compared with a commercial hybrid 8546IT. In each instance thepresent invention G4803 in hybrid combination carries advantages intothe hybrid when compared with the commercial hybrid. In hybrid 1 thereare positive advantages in vigor, stay green, black layer, and plantintegrity when compared with the commercial hybrid. The onlydisadvantage shown is in the early stand.

TABLE 6B Agronomic Traits G4803 as hybrid 2 G4803 as hybrid 2 vs 85461TEarly YEAR # Stand Adv Emp Adv Vigor Adv S50 Adv P50 Adv 2 yrs 48 89.40.2 6.1 0.6 5.9 0.6 75.0 −1.0 74.0 −1.0 data 48 89.2 5.5 5.4 76.0 76.0Ear Plant Stay Black Ht. Adv Ht. Adv Green Adv Layer Adv Plant Int Adv39.7 0.7 86.9 0.3 4.4 1.5 135.0 0.0 5.2 0.9 39.0 86.7 2.8 133.0 4.3Lines marked with the advantage information have data from the presentinbred in hybrid combination ADV = ADVANTAGE IT = Imidazolinoneherbicide resistance

-   -   The data in Table 6A and B shows the advantage or disadvantage        associated with the agronomic traits of the present inbred when        in hybrid combination when compared with a commercial hybrid        carrying a mutation giving IT resistance to that hybrid. The two        lines of data in Table 6a show one year of data. The two lines        of data in Table 6B show the combined data of two years. The        present invention when in hybrid combination 2 in the overall        data in Table 6B shows a positive advantage for early stand,        emergence, stay green, plant integrity, vigor. The only slight        disadvantage shown in this comparison is in the silking and        pollen ratings. The foregoing is set forth by way of example and        is not intended to limit the scope of the invention.        This invention also is directed to methods for producing a corn        plant by crossing a first parent corn plant with a second parent        corn plant wherein the first or second parent corn plant is an        inbred corn plant from the line G4803. Further, both first and        second parent corn plants can come from the inbred corn line        G4803 which produces a self of the inbred invention. The present        invention can be employed in a variety of breeding methods which        can be selected depending on the mode of reproduction, the        trait, and the condition of the germplasm. Thus, any breeding        methods using the inbred corn line G4803 are part of this        invention: selfing, backcrosses, hybrid production, crosses to        populations, haploid by such old and known methods of using        stock material that induces haploids and anther culturing and        the like.        All plants and plant cells produced using inbred corn line G4803        are within the scope of this invention. The invention        encompasses the inbred corn line used in crosses with other,        different, corn inbreds to produce (F1) corn hybrid seeds and        hybrid plants and the grain produced on the hybrid plant. This        invention includes plant and plant cells, which upon growth and        differentiation produce corn plants having the physiological and        morphological characteristics of the inbred line G4803.        Additionally, this maize can, within the scope of the invention,        contain: a mutant gene such as, but not limited to, the sugary 1        or shrunken 1 or waxy or AE or imazethapyr tolerant (IT or IR        TM) mutant gene; or transgenic genes such as but not limited to        insect resistant genes such as Corn Rootworm gene, Bacillus        thuringiensis (Cry genes), or herbicide resistant genes such as        Pat gene or Bar gene, EPSP, or disease resistant genes such as        the Mosaic virus resistant gene, etc., or trait altering genes        such as flowering genes, oil modifying genes, senescence genes        and the like. The methods and techniques for inserting, or        producing and/or identifying a mutation or a transgene into the        present invention through breeding, transformation, or mutating        are well known and understood by those of ordinary skill in the        art.

Various techniques for breeding and moving or altering genetic materialwithin or into the present invention (whether it is an inbred or inhybrid combination) are also known to those skilled in the art. Thesetechniques to list only a few are anther culturing, haploid production,(stock six is a method that has been in use for thirty years and is wellknown to those with skill in the art), transformation, irradiation toproduce mutations, chemical or biological mutation agents and a host ofother methods are within the scope of the invention. All parts of theG4803 plant including its plant cells produced using the inbred cornline are within the scope of this invention. The term transgenic plantrefers to plants having genetic sequences, which are introduced into thegenome of a plant by a transformation method and the progeny thereof.Transformation methods are means for integrating new genetic codingsequences into the plant's genome by the incorporation of thesesequences into a plant through man's assistance, but not by breedingpractices. The transgene once introduced into plant material andintegrated stably can be moved into other germplasm by standard breedingpractices.

Though there are a large number of known methods to transform plants,certain types of plants are more amenable to transformation than areothers. Transformation of dicots is usually achievable for example,tobacco is a readily transformable plant. Monocots can present sometransformation challenges, however, the basic steps of transformingmonocots have been known in the art for about 15 years. The most commonmethod of maize transformation is referred to as gunning ormicroprojectile bombardment though other methods can be used. Theprocess employs small gold-coated particles coated with DNA, which areshot into the transformable material. Detailed techniques for gunningDNA into cells, tissue, callus, embryos, and the like are well known inthe prior art. One example of steps that can be involved in monocottransformation are concisely outlined in U.S. Pat. No. 5,484,956“Fertile Transgenic Zea mays Plants Comprising Heterologous DNA EncodingBacillus Thuringiensis Endotoxin” issued Jan. 16, 1996 and also in U.S.Pat. No. 5,489,520 “Process of Producing Fertile Zea mays Plants andProgeny Comprising a Gene Encoding Phosphinothricin Acetyl Transferase”issued Feb. 6, 1996.

Plant cells such as maize can be transformed not only by the use of agunning device but also by a number of different techniques. Some ofthese techniques include maize pollen transformation (See University ofToledo 1993 U.S. Pat. No. 5,177,010); Whiskers technology (See U.S. Pat.Nos. 5,464,765 and 5,302,523); electroporation; PEG on Maize;Agrobacterium (See 1996 article on transformation of maize cells inNature Biotechnology, Volume 14, June 1996) along with numerous othermethods which may have slightly lower efficiency rates. Some of thesemethods require specific types of cells and other methods can bepracticed on any number of cell types.

The use of pollen, cotyledons, zygotic embryos, meristems and ovum asthe target issue can eliminate the need for extensive tissue culturework. Generally, cells derived from meristematic tissue are useful. Themethod of transformation of meristematic cells of cereal is taught inthe PCT application WO96/04392. Any number of various cell lines,tissues, calli and plant parts can and have been transformed by thosehaving knowledge in the art. Methods of preparing callus or protoplastsfrom various plants are well known in the art and specific methods aredetailed in patents and references used by those skilled in the art.Cultures can be initiated from most of the above-identified tissue. Theonly true requirement of the transforming plant material is that it canform a transformed plant.

The DNA used for transformation of these plants clearly may be circular,linear, and double or single stranded. Usually, the DNA is in the formof a plasmid. The plasmid usually contains regulatory and/or targetingsequences which assists the expression of the gene in the plant. Themethods of forming plasmids for transformation are known in the art.Plasmid components can include such items as: leader sequences, transitpolypeptides, promoters, terminators, genes, introns, marker genes, etc.The structures of the gene orientations can be sense, antisense, partialantisense, or partial sense: multiple gene copies can be used. Thetransgenic gene can come from various non-plant genes (such as;bacteria, yeast, animals, and viruses) along with being from plants.

The regulatory promoters employed can be constitutive such as CaMv35S(usually for dicots) and polyubiquitin for monocots or tissue specificpromoters such as CAB promoters, MR7 described in U.S. Pat. No.5,837,848, etc. The prior art promoters, includes but is not limited to,octopine synthase, nopaline synthase, CaMv19S, mannopine synthase. Theseregulatory sequences can be combined with introns, terminators,enhancers, leader sequences and the like in the material used fortransformation.

The isolated DNA is then transformed into the plant. After thetransformation of the plant material is complete, the next step isidentifying the cells or material, which has been transformed. In somecases, a screenable marker is employed such as the beta-glucuronidasegene of the uidA locus of E. coli. Then, the transformed cellsexpressing the colored protein are selected. In many cases, a selectablemarker identifies the transformed material. The putatively transformedmaterial is exposed to a toxic agent at varying concentrations. Thecells not transformed with the selectable marker, which providesresistance to this toxic agent, die. Cells or tissues containing theresistant selectable marker generally proliferate. It has been notedthat although selectable markers protect the cells from some of thetoxic affects of the herbicide or antibiotic, the cells may still beslightly affected by the toxic agent by having slower growth rates. Ifthe transformed material was cell lines then these lines are regeneratedinto plants. The cells lines are treated to induce tissuedifferentiation. Methods of regeneration of cellular maize material arewell known in the art.

A deposit of at least 2500 seeds of this invention will be maintained byGarst Seed Company, 2369 330th Street, Slater, Iowa 50244. Access tothis deposit will be available during the pendency of this applicationto the Commissioner of Patents and Trademarks and persons determined bythe Commissioner to be entitled thereto upon request. All restrictionson availability to the public of such material will be removed uponissuance of a granted patent of this application by depositing at least2500 seeds of this invention at the American Type Culture Collection(ATCC), at 10801 University Boulevard, Manassas, Va. 20110. The date ofdeposit was Mar. 27, 2006. The ATCC number of the deposit is PTA-7453and on day of Apr. 13, 2006 the deposit was found viable when tested.The deposit of at least 2500 seeds will be from the same inbred seedtaken from the deposit maintained by Garst Seed Company. The ATCCdeposit will be maintained in that depository, which is a publicdepository, for a period of 30 years, or 5 years after the last request,or for the effective life of the patent, whichever is longer, and willbe replaced if it becomes nonviable during that period.

Additional public information on some ZS designations may be availablefrom the PVP Office, a division of the US Government.

Accordingly, the present invention has been described with some degreeof particularity directed to the preferred embodiment of the presentinvention. It should be appreciated, though, that the present inventionis defined by the following claims construed in light of the prior artso that modifications or changes may be made to the preferred embodimentof the present invention without departing from the inventive conceptscontained herein.

1. Inbred corn seed of the line designated G4803, wherein representativesamples of seed of said line has been deposited in the ATCC as accessionnumber PTA-7453.
 2. A corn plant produced by growing the seed ofclaim
 1. 3. A tissue culture of regenerable cells produced from the cornplant of claim
 2. 4. A tissue culture according to claim 3, wherein theregenerable cells are from a tissue, wherein the tissue is: leaf,pollen, embryo[s], roots, root tip[s], meristem, ovule, anther[s], silk,flower[s], kernel[s], ear[s], cob[s], husk[s] or stalk[s].
 5. A cornplant regenerated from the tissue culture of claim 3, wherein theregenerated plant has all of the physiological and morphologicalcharacteristics of a corn plant of inbred line designated G4803, whereinrepresentative seed of said inbred line has been deposited in the ATCCas accession number PTA-7453.
 6. A method of producing hybrid seedcomprising the following steps: (a) planting, seeds of corn inbred lineG4803 of which representative seed samples have been deposited in theATCC as accession number PTA-7453 and another inbred line, one of saidinbred lines not releasing pollen; (b) allowing pollination of thenon-pollen releasing inbred to occur; and (c) harvesting seeds producedon the non-pollen releasing inbred.
 7. A method of producing an F1hybrid corn seed comprising: crossing the plant in claim 2 with adifferent maize plant and harvesting the resultant F1 hybrid corn seed.8. A method according to claim 7 wherein hybrid plants are grown fromseed of claim
 7. 9. A method for producing a herbicide resistant cornplant comprising inserting into the corn plant of claim 2, at least onetransgene that confers herbicide resistance.
 10. The pollen of a cornplant produced by the seed of claim
 1. 11. Seed produced by selfing theplant according to claim 2 wherein seed produce corn plants having allof the physiological and morphological characteristics of a corn plantof inbred line G4803, representative sample of seed of said inbred linehaving been deposited in the ATCC as Accession No. PTA-7453.
 12. Anherbicide resistant corn plant produced by the method of claim
 9. 13. Amethod of producing an insect resistant corn plant comprising insertinginto the corn plant of claim 2 a transgene that confers insectresistance.
 14. An insect resistant corn plant produced by the method ofclaim
 13. 15. The corn plant of claim 14, wherein the transgene encodesa Bacillus thuringiensis endotoxin.
 16. A method of producing a diseaseresistant corn plant comprising inserting into the corn plant of claim 2a transgene that confers disease resistance.
 17. A disease resistancecorn plant produced by the method of claim 16.